Ask Your Question

Revision history [back]

click to hide/show revision 1
initial version

Navigation stack, no laser


I have put in place a (custom) mobile robot with a drive controller (taking a desired twist and outputting required wheel velocities) and joint controllers which allow me to actually get the required wheel velocities. This is all done in ros_control.

Now I would like to drive my robot providing it with a desired trajectory (or desired target) and not with a twist (i.e. specify my trajectory in 6D position space, not in twist space). From what I understand, this is the aim of the navigation stack. But the navigation stack's wiki actually states the stack

requires a planar laser mounted somewhere on the mobile base. This laser is used for map building and localization.

Unfortunately my robot is not planning to integrate such a device. Does that mean the stack is unusable to me?

I am not sure I understand why there is such a hard requirement. There are plenty of uses cases for using other localization technique (e.g. triangulation, or video...), or even no localization technique at all (and thus accept drifts), and still expecting to transform a desired positional trajectory into desired velocities (to feed the controllers). Actually I am pretty sure some low layer of the navigation is doing just that. So isn't it accessible to robots having no laser?

Is it me not understanding things or is there something else? As you understood I am looking for a tool taking a desired trajectory or position in input and outputting corresponding twists...